In recent years, Internet of Things (IoT) which is a technology for connecting various objects in the world to the Internet has been noticed. Effective utilization of electronic devices is preferable in view of contribution to realization of IoT.
For example, wearable devices which are electronic devices worn on human bodies become popular. Such wearable devices can supply valuable information necessary to users by acquiring information regarding human bodies or actions of the users with high precision. Therefore, wearable devices are requested to have excellent constant wearing properties or constant connectivity to computer communication networks such as the Internet to analyze the acquired information rapidly.
To meet such requests, the following PTL 1 discloses a terminal device that ensures constant connectivity through multi-hop communication so that the outside (family members, friends, or the like) can be informed of safety or situation of a user when natural disasters such as large earthquakes, fires, tropical storms, or flood damages occur.